TWI483772B - A multi-phase reactor system - Google Patents

Description

Multiphase reactor system

The current disclosure relates to a multiphase reactor system for carrying out a gas-liquid or gas-liquid-solid reaction and thereby performing a reaction process.

Many chemical reactions require reactor system structures such as efficient production, optional product selection, and negligible production of semi-finished and by-products. Multiphase reactor systems are designed to perform gas-liquid or gas-liquid-solid reactions. These reactor systems typically consist of a reaction vessel, including a turntable and a stirring device, such as an impeller. Therefore, commonly referred to as "stirred tank reactor" or "STR", the reaction vessel typically includes a gas exhaust pipe to disperse a large amount of gas in the liquid medium. All of these multiphase reactor systems are commonly used in fermentation, hydrogenation, phosgenation, neutralization, chlorination and oxidation reactions in which the liquid and gas phases are brought into intimate contact to achieve the desired yield and yield. rate. In addition, the reliable operation of these systems depends to a large extent on the correct flow distribution and hydrodynamic behavior.

The exhaust pipe configuration and geometry of the reaction vessel, impeller, and gas are primarily governed by the degree of homogeneity, the required mass transfer rate, solids suspension, and energy consumption. Sometimes, the nature of the chemical reaction requires ancillary equipment or internal components of the container, such as a container sheath, internal heating or cooling coils, and a throwing device.

In general, in a gas-liquid or gas-liquid-solid reaction, gas is ejected from the bottom of the reaction vessel, and the feedstock is injected from the top or the middle of the vessel. Unreacted gas From the top liquid surface, enter the tower top system. Typically such gases carry droplets to the overhead system which can cause fouling and corrosion within the overhead system. During the exothermic reaction, the heat of the reaction continues to boil the reactor liquid or reaction medium to gasification to maintain the desired reaction temperature. These vapors also carry droplets into the overhead system. In a three-phase reaction, suspended solids from the reaction medium are also carried by the vapor or unreacted gases to the overhead system, resulting in a solid combination of the overhead system and solid deposits on the inner walls of the headspace of the vessel. A throwing device is provided in these cases. In known heterogeneous reactor systems, a throwing device is provided in the vicinity of the operable top of the reaction vessel, typically on the agitator shaft of the reaction vessel to spray recycled liquid on the surface of the reaction vessel and the liquid release surface of the vessel inner wall and/or Or fresh liquid. The spraying of the liquid reduces the fouling of the inner wall and the clogging of the condenser by washing the inner wall of the reaction vessel and scrubbing the gas remaining in the reaction vessel.

An example of a heterogeneous reaction is the oxidation of an aralkyl group in a liquid reaction medium (e.g., para-xylene), such as a terephthalic acid manufacturing process from para-xylene. During this process, air is sprayed through the nozzle near the tip of the axial flow impeller in the reaction medium of the solvent. The heat generated by the exothermic oxidation reaction is dissipated by vaporization of the solvent and water produced by the oxidation of p-xylene. The temperature in the reaction vessel is controlled by the vaporization of the solvent and water, as well as the condensing flow of the overhead vapor. Crude terephthalic acid is recovered from the reaction product by crystallization and filtration.

Most of the terephthalic acid crystals are suspended in the liquid phase and can be polymerized on the inner wall of the reaction vessel. This results in a reduction in the amount of operation of the reactor, which reduces the residence time of the reaction, resulting in the formation of intermediate by-products. Vaporization of the solvent in the reaction vessel also carries fine solid particles to the overhead condenser system, causing blockage of the overhead condenser. Uneven heating and cooling of the walls of the reaction vessel can also cause thermal stresses in the vessel casing and can result in leakage of the casing. In a vessel such as a continuous boiling oxidation reaction in a terephthalic acid production plant, the overhead vapor stream of condensed water is fed back into the reaction vessel through the top and bottom reflux lines. The purpose of the top reflux is to wash the walls of the reaction vessel to avoid solid deposits and scrubbing into the overhead condenser system containing solid particles. Steam. The purpose of bottom reflux is to increase the conversion of p-xylene to terephthalic acid and to reduce acetic acid combustion by reducing the disadvantages of the reaction vessel.

However, conventional throwing devices include a rotating, flat disc consisting of a plurality of vertically raised straight blades that extend radially outward from the central hub of the disc to its periphery. The condensate is returned to the reaction vessel through a conduit above the throwing device. The condensate is injected from above the throwing device and then radially diverge from the throwing device to the outside of the reaction vessel. These throwing devices are located in the "headspace" portion above the container, covering only a portion of the cross section of the reaction vessel, and thus do not completely eliminate the above problems. Some such conventional throwing devices are disclosed in the prior art below.

U.S. Patent No. 4,422,626 discloses an apparatus for building and repairing industrial furnace refractory linings. The apparatus includes a turntable for centrifugally throwing a rotating particulate refractory material to a portion of the liner to be repaired, comprising a row of horizontal perforated hollow bolts for spraying water to the inlet conduit of the annular cross section, whereby the material transferred to the disc through the conduit is uniformly wetted .

WO2008036370 discloses a liquid-gas phase reactor system comprising a thrower fixed to an extended drive shaft passing through at least a portion of the upper portion of the reaction vessel

A major disadvantage of known throwing devices is that the majority of the condensate is only distributed over a limited cross section of the reaction vessel, in fact only a small amount of condensate reaches the reaction wall. A further disadvantage is that the liquid tends to distribute large droplets rather than finely divided droplets. This causes the solids to migrate in the overhead condensation system and form a solid deposit on the reaction walls. Thus, such systems experience fouling of the inner wall, blockage of the condenser, and poor mixing of the condensate with the liquid reaction medium. In addition, known throwing devices are less effective in dissipating the heat generated by the oxidation reaction. For example, the exothermic oxidation of an aromatic alkyl group, the majority of the heat generated by the reaction accumulates in the middle of the liquid reaction medium. These hot spots can lead to unwanted reactions, solvent consumption and increased steam generation, all of which increase the high operating costs and are inefficient. Moreover, uneven heating and cooling of the walls of the reaction vessel may cause thermal stresses in the walls of the vessel which may cause leakage of the casing.

Therefore, it is considered necessary to provide an improved throwing device for uniformly distributing reflux (condensate) liquid through the inner wall of the reaction vessel in a multi-phase reactor system and optimizing the maximum amount of reflux according to the process requirements, which will overcome the front The disadvantages of known throwing devices are mentioned.

aims

One of the specific examples of currently disclosed goals, at least met, is as follows: The current disclosed goal is to improve one or more of the problems in the prior art, or at least provide a useful alternative.

Accordingly, the presently disclosed object is to provide an improved throwing device for a multiphase reactor system, minimizing the polymerization of solids in the overhead system and the deposition of solids on the shell walls in the headspace of the reaction vessel, by cleaning the solid deposit inner shell. Walls and scrubs of solid particles from the venting of steam and exhaust gases, thereby reducing internal casing fouling and overhead system blockage to extend reactor operating life.

Another object disclosed herein is to provide a throwing device for the multiphase reactor system to uniformly spray a liquid and/or liquid stream 360° on the inner wall of the reaction vessel of the vapor space.

However, another goal currently disclosed is to provide a throwing device for the multiphase reactor system to optimize the maximum flow rate according to process requirements.

Other objects and advantages disclosed herein will become more apparent upon reading the following description in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.

According to the present disclosure, a multiphase reactor system has been provided for performing a heterogeneous reaction, the reactor system comprising a reaction vessel, and a throwing device fixed to the agitating shaft closest to the top intermediate position of the reaction vessel operation, wherein the throwing device comprises a fixture The fixing device is composed of a vertical disc and a cover plate, the cover plate at least partially covering the agitating shaft to form a space for collecting liquid, and at least one spraying device is provided together with the fixing device for passing The throwing track path on the rotating shaft rotating zone distributes the liquid on the inner wall of the reaction vessel.

Typically in accordance with the present disclosure, the fixture is placed in contact with the action of the liquid inlet to receive the liquid.

The throwing device typically rotates in synchronism with the agitator shaft.

According to the present disclosure, it is preferred that the spray device comprises at least one spray tube provided on a vertical disc.

Generally, in accordance with the present disclosure, the spray device comprises a plurality of equally spaced round tubes provided on a vertical disc that can be used to form a liquid umbrella to scrub the steam generated by the solids during the reaction prior to exiting the reaction system.

According to the present disclosure, it is preferred that the length of the circumferential tube is shorter than the spray tube.

According to the present disclosure, alternatively, the spray device includes at least one concave vane on the cover plate which can be used to prevent spillage of liquid and form a liquid umbrella to scrub the steam generated by the solid during the reaction prior to exiting the reaction system.

According to the present disclosure, the diameter of the throwing device can generally be used to provide an exit rate of steam from the reaction system, ranging from 1 to 5 meters per second.

According to the present disclosure, a method for oxidizing an aromatic alkyl group in a multiphase reactor system is disclosed herein, the method comprising the steps of: introducing a liquid reaction medium comprising an aromatic alkyl group in a reaction vessel in a reactor system And a solvent; ejecting air into the liquid reaction medium at a bottom position closest to the action of the reaction vessel, causing oxidation to produce an effect, generating heat and causing vaporization of the liquid reaction medium; at least condensing a portion of the liquid reaction medium vapor to produce a reflux liquid; The throwing device closest to the active top of the reaction vessel in the intermediate position returns the first portion of the returning liquid to the reaction vessel to clean the solid deposits on the inner wall of the reaction vessel and scrub the solid particles from the exhaust steam and the exhaust gas, wherein The throwing device comprises a fixing device for collecting the reflux liquid by a vertical circumferential disk and at least partially covering the stirring shaft The cover plate of the body is composed of at least one spraying device, and the returning liquid is distributed through the throwing track path on the rotating shaft of the stirring shaft; and the second portion of the returning liquid is returned to the liquid reaction medium.

100‧‧‧ throwing device

102‧‧‧Agitator shaft

104‧‧‧ concave blade

106‧‧‧Spray tube

107‧‧‧ Cover

108‧‧‧Vertical circumferential disk

110‧‧‧ Arrangement

200‧‧‧ throwing device

202‧‧‧Agitator shaft

204‧‧‧ Cover

206‧‧‧Spray tube

208‧‧‧Circular tube

210‧‧‧Circular tube

212‧‧‧Circular tube

214‧‧‧Vertical circumferential disk

300‧‧‧ throwing device

302‧‧‧Agitator shaft

310‧‧‧Circumferential or spiral tube

314‧‧‧Circular disk

The present disclosure will now be described with the aid of non-limiting figures, in which Figure 1A illustrates a side view of a first embodiment of a multiphase reactor system throwing device; Figure 1B illustrates the first of a multiphase reactor system throwing device Example top view; Figure 2A shows a side view of a second embodiment of a multiphase reactor system throwing device; Figure 2B shows a top view of a second embodiment of a multiphase reactor system throwing device; Figure 3 shows a throwing plate design .

The disclosure will now describe embodiments relating to the scope and limits of non-limiting disclosure. This description is provided purely by way of example and illustration.

The embodiment and many of its features and advantageous features are explained in the following description with reference to the non-limiting embodiments. Descriptions of well-known components and processing techniques are omitted herein so as not to unnecessarily obscure the embodiments. The examples used herein are merely to assist in understanding the methods that may be used in the embodiments, and to further enhance these skills in the practice of the embodiments. Accordingly, the examples should not be construed as limiting the scope of the examples.

The present disclosure is directed to multiphase reactor systems for performing heterogeneous reactions, including gas-liquid or gas-liquid-solid reactions, particularly oxidation of aromatic alkyl groups. The multiphase reactor system comprises a reaction vessel, a single or multiple impellers, a gas or air atomizer, a feed port and/or a liquid inlet, and a throwing device attached to the agitator shaft. The throwing device on the mounting and agitating shaft is used in its vapor space for 360° uniform dispersion of liquid and/or reflux liquid on the inner wall of the reaction vessel to keep the inner wall of the reaction vessel clean and also to be scrubbed from the reaction vessel. Solid particles carried by exhaust gases and steam.

The currently disclosed throwing device ensures complete wetting and cleaning of the headspace of the reaction vessel The inner wall and brush the reaction steam. The throwing device is attached to the agitator shaft disposed in the middle and extends from the top of the operating portion of the reaction vessel through at least a portion of the length of operation of the reaction vessel. The throwing device is placed closest to the top of the reaction vessel operation. The throwing device comprises a fixture consisting of a vertical circumferential disk and a cover plate at least capable of covering a portion of the rotating shaft to collect liquid. The fixture is provided with at least one spray device that can be distributed over the liquid from the fixture on the inner wall of the reaction vessel by a throwing track path on the agitator shaft rotation zone. The spray device includes at least one spray tube disposed on the vertical circumferential disk. The spray device may contain a plurality of equally spaced circumferential tubes distributed over the vertical circumferential disk and having a shorter length than the spray tube. The circumferential tube may or may not be placed on the same line as the spray tube. The circumferential tube can be used to form a liquid umbrella for scrubbing the steam generated during the solids reaction and is therefore only used to clean the steam and exhaust gases exiting the reaction vessel. The spray device may also include at least one concave vane attached to the cover. The concave vanes prevent liquid from escaping from the fixture and are also suitable for forming a liquid umbrella to scrub the steam generated during the solids reaction.

A portion of the rotating shaft surrounds the vertical circumferential disk and the annular cover plate and is disposed at an edge of the circumferential disk to form an annular space between the rotating shaft and the circumferential disk for receiving liquid. The spray device typically comprises at least one spray tube that is attached to a vertical circumferential disk. More than one isometric spray tube has a suitable diameter and is designed to provide sufficient clearance between the inner wall of the reaction vessel and the discharge point of the conduit. These tubes are attached to the circumferential disk of the throwing device for spraying the liquid collected from the annulus of the inner wall of the reaction vessel. The spray device may more include one or more equally spaced concave vanes on the throwing device cover. Concave blades have the appropriate blade height and length, equal to the width of the cover. The spray device may also contain a plurality of equidistant circumferential tubes provided on the circumferential disk.

Multiphase reactor systems are suitable for the oxidation of aromatic alkyl groups, such as para-xylene. The liquid reaction medium typically comprises an aromatic alkyl group and a solvent, acetic acid, which is injected in a reaction vessel of the multiphase reactor. Air is injected into the liquid reaction medium by a gas injector provided by the following liquid grade to provide a source of oxygen for the initiation of the oxidation reaction. Heat generated by an exothermic oxidation reaction The vaporization of the solvent and the water produced by the oxidation of the aromatic alkyl group are dispersed. The vaporized solvent is concentrated in the overhead condenser, and less than 50% of the total condensate (reflux liquid) is circulated for use in the liquid reaction medium, exceeding 50% of the total condensate by the throwing device tool located at the top of the reactor vessel operation The bottom is returned to the reactor vessel through the return line. The reactor system includes a top return line that delivers reflux liquid to the fixture through the liquid inlet of the throwing device.

The recycled liquid that falls into the fixture is distributed on the surface of the liquid and is also distributed on the inner wall of the reaction vessel. It is necessary to determine the actual amount of liquid flow on the fixture and the flow of liquid through the rotating nozzle and the circumferential tube to estimate the rate of liquid passing therethrough. The liquid sprayed on the inner wall of the reactor conforms to the amount of liquid passing through the nozzle. The remaining liquid in the reaction vessel is distributed over the liquid medium.

The agitation speed in the stirred vessel reactor is controlled by the per unit volume and maximum transfer amount required for the desired reaction rate. Since the thrower is placed on the agitator shaft, its rotation is determined by the agitator speed. Therefore, the throwing device is required to be designed for the known agitator shaft speed. The vapor remaining in the reaction vessel releases liquid or unreacted gas flows through the area between the vessel wall and the throwing device. The rate of this gas determines the diameter of the throwing device. Calculate the diameter of the throwing device so that the rate at which steam is removed from the reaction vessel is approximately 1-5 meters per second.

The presently disclosed embodiments are in Figures 1 and 2 of the supplementary figures.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A shows a first side view of an embodiment of a throwing device disclosed. The throwing device 100 is generally in the form of a barrel, and the portion including the vertical circumferential disk 108 and the cover plate 107 covering the stirring shaft 102 constitutes a fixing means. The array 110 includes a plurality of concave vanes 104 disposed over the cover plate 107 . The throwing device 100 rotates in synchronization with the agitating shaft 102 . The throwing device 100 includes a spray device including a plurality of spray tubes 106 . The fixture receives the return liquid. The reflux liquid flows in the rotary spray pipe 106 in the entire cross section of the inner wall of the reaction vessel. The concave vanes 104 prevent liquid from escaping in the fixture. Moreover, the concave vanes 104 are adapted to form a flow recirculating liquid umbrella capable of scrubbing the steam and exhaust gases generated during the solids reaction to provide clean steam and exhaust gases at the outlet.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1B shows a first top view of an embodiment of a throwing device disclosed. Figure 1B shows that the array 110 includes a plurality of concave vanes 104 mounted to the cover plate 107 . An open space is formed between the agitator shaft 102 and the array 110 to allow the returning liquid to flow in an umbrella form which aids in scrubbing the steam and exhaust gases generated during the reaction. The spray pipe 106 disperses the reflux liquid at 360 ° C on the inner wall of the reaction vessel.

Supplementary Figure 2A shows a second side view of an embodiment of the throwing device disclosed. The throwing device 200 includes a vertical circumferential disk 214 cover 204 that covers the portion of the agitator shaft 202 to form a fixture. The throwing device 200 includes a spray device including a plurality of spray tubes 206 and a plurality of circumferential tubes 208, 210 & 212 . Many of the 208, 210 & 212 are of equal diameter and length and are equally spaced on the circumferential disk of the throwing device, 21,420 . The length of the circumferential tube 208, 210 & 212 is shorter than the length of the spray tube 206 . Many circumferential tubes 208, 210 & 212 may or may not be placed coaxially with the spray tube 206 . The fixture receives the return liquid. The reflux liquid flows in the rotating spray tube 206. A plurality of circumferential tubes 208, 210 & 212 are distributed over the entire cross section of the inner wall of the reaction vessel. A plurality of circumferential tubes 208, 210 & 212 are adapted to form a reflux liquid umbrella to scrub the steam generated during the solids reaction and to provide clean steam and exhaust gases at the outlet of the reaction vessel.

Supplementary Figure 2B shows a second top view of an embodiment of the throwing device disclosed. 2B shows the fixture formed between the agitator shaft 202 and the cover plate 204 . The arrangement 206 of spray tubes and the plurality of circumferential tubes 208, 210 & 212 are clearly visible on the circumferential disk 214 from the top view.

The kinetic energy of the liquid at the outlet of the spray tube is the extra energy created by the static head developed by the liquid from the fixture, and the energy acts on the liquid due to centrifugal force. In a rotating tube, the centrifugally driven liquid flow is affected by the Earth's rotation bias force, except for the pressure gradient in the annular tube. The calculation of the liquid velocity at the exit of the rotating tube or rotating vessel is caused by the total static pressure head The difference and centrifugal force subtract the friction loss of the rotating tube and the opening. The trajectory of the projectile that it follows when the liquid is thrown out of the pipe or tube at the initial liquid rate. The velocity of the liquid at the outlet of the spout/tube determines the distribution pattern of liquid flowing through the open space of the cross-section of the reaction vessel and the height of most droplets striking the inner wall of the reaction. The liquid enters the vertical plane for the first time at the initial velocity of the liquid and then moves to the two dimensions of gravity and the friction provided by the upward steam or gas. The time required to flow a droplet between the throwing device and the wall of the vessel, using the equation of motion estimate, considers the acceleration along the horizontal axis to be zero. The vertical distance of the droplet hitting the vessel wall is estimated using the equation of motion based on the known movement time under the influence of the steam rise rate and the friction provided by gravity. The rate of liquid flow in the spray tube/tube or throwing device can be optimized by varying the number of tubes, tube diameter, number of circumferential tubes, circumferential tube size, and number of concave vanes to confirm the desired location of the droplets striking the walls of the vessel.

An embodiment of the circumferential disk is illustrated in Figure 3 of the additional figures. The throwing device 300 shows that the circumferential disk 314 encloses a stirring shaft 302 and has a plurality of equidistant circumferences or spiral tubes 310 that are typically spaced 10 mm apart. The hole rate is estimated by the hole secretary calculation and the projectile equation is used to estimate where the liquid falls on the inner wall. The rate 314 of returning liquid over the circumference of the circumferential disk is based on the centrifugal force using the agitation speed and the throw diameter on the circumferential disk surface. The % free area 314 on the circumferential disk is different from the number and diameter of the tubes. This type of method in which the reflux liquid will fall on the inner wall of the reaction vessel is optimized. The trajectory of the liquid jet will be raised by the steam/gas flowing upward. Therefore, the liquid injection conforms to a higher position than the calculated container wall.

Technical advantages

The throwing device in a multiphase reactor system, as described in the present disclosure, has several technical advantages including, but not limited to, implementation: the throwing device uniformly disperses the reflux liquid 360° on the inner casing wall of the vessel during the reaction; The throwing device scrubs the solid particulates from the exhaust gas and steam from the reaction vessel; the throwing device optimizes the total return flow according to process requirements, and the remaining reflux can be transferred to the bottom of the vessel to provide a cooled bottom reflux.

Throughout this specification, the words "include" or such as "include" or "include" It will be understood that the elements, integers or steps, or a group of elements, integers or steps, or any other elements, integers or steps, or a group of elements, integers or steps.

The use of "at least" or "at least one of" expressions suggests the use of one or more elements or components or quantities, as such use may be in the embodiments of the present disclosure to obtain one or more desired objectives or results.

Any discussion of text, conduct, materials, equipment, articles, or similar situations that have been included in this description is purely for the purpose of providing a background for the disclosure. It does not recognize any or all of the problems of the prior art component or common general knowledge of the relevant fields of this disclosure, as it already exists prior to the priority date of this application.

The values mentioned for many physical parameters, dimensions or quantities are only approximations and are assumed to be higher/lower than the values of the parameters, dimensions or quantities assigned to the scope of the disclosure, unless the evidence of the contrary is explicitly stated in the specification.

The foregoing description of the specific embodiments will fully disclose the general nature of the embodiments, and by applying the current knowledge, others can easily modify and/or adapt various applications, such as a particular embodiment without departing from the general concept. These adaptations and modifications are intended to be understood within the meaning and range of equivalents of the embodiments of the disclosure. The wording and terminology used herein is for the purpose of description and not for the purpose of limitation. Accordingly, while the embodiments have been described in the foregoing embodiments, those skilled in the art will understand that the embodiments can be practiced within the spirit and scope of the invention.

100‧‧‧ throwing device

102‧‧‧Agitator shaft

104‧‧‧ concave blade

106‧‧‧Spray tube

107‧‧‧ Cover

108‧‧‧Vertical circumferential disk

110‧‧‧ Arrangement

Claims (9)

A multiphase reactor system for performing a multiphase reaction, the reactor system comprising a reaction vessel having a throwing device fixed to an agitating shaft at an intermediate position adjacent to an operating top of the reaction vessel, wherein the throwing device comprises a fixing device, a vertical circumferential disk and a cover plate, the cover plate at least partially covering the agitating shaft to form a space for collecting liquid, and the fixing device is provided with at least one spraying device in the reaction vessel through a throwing trajectory path on the rotating shaft rotating region The above liquid is distributed on the inner wall. A reactor system according to claim 1, wherein said holding means is arranged to be operatively connected to the liquid inlet to receive the liquid. The reactor system of claim 1, wherein the above-described throwing device rotates in synchronization with the rotating shaft. A reactor system according to claim 1, wherein said spraying means comprises at least one spray pipe provided on said vertical circumferential pipe. The reactor system of claim 1, wherein said spraying means comprises a plurality of equidistant circumferential tubes provided by said vertical circumferential disk, said circumferential tube being adapted to form said liquid umbrella, capable of scrubbing steam generated during solid reaction, excluding said Before the reaction system. The reactor system of claim 5, wherein the circumferential tube is shorter than the length of the spray tube. The reactor system of claim 1, wherein said spraying means comprises at least one concave vane provided on said cover plate, said concave vane being adapted to prevent said liquid from overflowing, and capable of forming said liquid umbrella for scrubbing steam generated during solid reaction Before it exits the above reaction system. The reactor system of claim 1 wherein the diameter of said throwing device is adapted to provide The steam outlet rate from the above reactor system ranges from 1 to 5 meters per second. A method for oxidizing an aromatic alkyl group in a multiphase reactor system, the method comprising the steps of: introducing a liquid reaction medium comprising an aromatic alkyl group and a solvent in a reaction vessel of the above reactor system; operating in a reactor vessel closest to the above a bottom position ejecting air into the liquid reaction medium to cause an oxidation effect, generating heat and causing vaporization of the liquid reaction medium; at least condensing a portion of the vapor of the liquid reaction medium to produce a reflux liquid; by fixing the stirring shaft at an intermediate position The throwing device closest to the top of the reaction vessel returns the first portion of the reflux liquid to the reaction vessel to clean the solid deposits on the inner wall of the reaction vessel and scrub the solid particles from the exhaust steam and the exhaust gas, wherein the throwing device The invention comprises a fixing device consisting of a vertical circumferential disk and a cover plate at least partially covering the stirring shaft to collect the returning liquid, wherein the fixing device is provided with at least one spraying device, and the recirculation is distributed through a throwing track path on the rotating shaft rotating region Liquid; and return to the above A second portion of the liquid stream to the liquid reaction medium.